Thanks for the suggestion! I'm hoping to never have to take the hoses off again so that would actually be fine. The local Oreillys carries the stuff.

EDIT: After thinking about it, doesn't copper cause corrosion when in contact with steel?

 

Statue of Liberty is (or was) copper on top of cast iron the galvanic corrosion got to the point where they had to replace the entire inner structure will stainless steel. For carbon steel it will be less but still a factor.

 

I've used the several containers of both the spray and wipe on stuff on bare cast iron and never seen a rust deposit form. Mostly because no air gets to it I suspect.

Read the manufacturers usage and see if it fits your application. I used it any time a cork or paper gasket need sealed and that includes most old style water pumps. It never leaks or causes issues...

 

Thanks for the info!

 

I really went down a OCD worm hole with this. I looked at just using spray paint but apparently most are not great for direct to metal and most have temp limits of 200f...So then I started looking at higher temp paint and they all either have long cure times or require heating for curing. ..And then there is the primer. It's even harder to find a primer, especially self etching, that can be stable above 200f and then the self etching primers require a sealer so I thought about just chemically etching the metal for adhesion which has the side benefit of producing a protective coating of zinc phosphate but then you can't spray enamel over zinc phosphate because alkyds react with the zinc phosphate and produce a layer of soap underneath the enamel which will cause it to eventually fail. You have to use epoxy over zinc phosphate which isn't cheap. etc etc etc. So definitely went OCD on this. Long story short, I have bought so many new parts for this car I couldn't justify taking a shortcut now and just ordered all of the o-rings/seals and a new coolant line. Thanks for the help though. I really appreciate it.

 

The same reason you don't use grease around brake components like houses, caliper seals, caliper boots, slave cylinder components. It swells swellubber to point of failure.

 

^^^ haha! At least it was educational and it's only money! You're doing great!

 

No paint I've used so far will last long term on a coolant pipe. I currently have one painted with Rust Bullet we'll see how it holds up. This stuff has extreme bond strength I painted a spare tire hold down bolt and washer the latter gets friction from the bolt as you tighten, the only paint I've used that doesn't immediately get scraped off. Does anyone know what Rust Bullet actually is? The fumes are extreme, I think it is a polyurethane base but could be completely wrong. I've dabbled with electroplating but didn't get good results.

POR-15 high temp is holding up great on an exhaust I painted, but they recently banned it in Canada due to toxicity.
This is the correct choice, everything else is an experiment.